Background Many patients with inflammatory bowel disease (IBD) have transitioned from an infliximab originator to a biosimilar. However, some patients retransition to the originator (i.e. stop biosimilar and reinitiate the originator). Whether this sign of potential unsatisfactory treatment response is specifically related to the infliximab biosimilar or the patient and/or the disease including patients' beliefs on the biosimilar is unclear. Objectives We aimed to compare the risk of and reasons for infliximab discontinuation between retransitioned patients and those remaining on biosimilar. Design Non-interventional, multicentre cohort study. Methods IBD patients who transitioned from infliximab originator to biosimilar between January 2015 and September 2019 in two Dutch hospitals were eligible for this study. Retransitioned patients (retransitioning cohort) were matched with patients remaining on biosimilar (biosimilar remainder cohort). Reasons for discontinuation were categorised as the unwanted response (i.e. loss of effect or adverse events) or remission. Risk of unwanted discontinuation was compared using Cox proportional hazards models. Results Patients in the retransitioning cohort (n = 44) were younger (median age 39.9 versus 44.0 years), more often female (65.9% versus 48.9%) and had shorter dosing intervals (median 48.5 versus 56.0 days) than in the biosimilar remainder cohort (n = 127). Infliximab discontinuation due to unwanted response was 22.7% in the retransitioning and 13.4% in the biosimilar remainder cohort, and due to remission was 2.3% and 9.4%, respectively. Retransitioned patients are at increased risk of discontinuing due to unwanted response compared with biosimilar remainder patients (adjusted HR 3.7, 95% CI: 1.0-13.9). Patients who retransitioned due to an increase in objective disease markers had higher discontinuation rates than patients who retransitioned due to symptoms only (66.7% versus 23.7%). Conclusion Retransitioned patients are at increased risk of infliximab discontinuation due to unwanted response. Retransitioning appeared related to the patient and/or disease and not the product. Clinicians might switch patients opting for retransitioning to other treatment regimens.

中文翻译：

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对于转用原研药和仍使用生物仿制药的炎症性肠病患者，停止英夫利昔单抗治疗。

背景 许多炎症性肠病 (IBD) 患者已从英夫利昔单抗原研药转变为生物仿制药。然而，一些患者会重新转向原研药（即停止生物仿制药并重新开始原研药）。这种潜在的不满意治疗反应的迹象是否与英夫利昔单抗生物仿制药或患者和/或疾病（包括患者对生物仿制药的信念）具体相关尚不清楚。目的 我们的目的是比较重新转换患者和仍在使用生物仿制药的患者之间停用英夫利昔单抗的风险和原因。设计非干预性、多中心队列研究。方法 2015 年 1 月至 2019 年 9 月期间在荷兰两家医院从英夫利昔单抗原研药过渡到生物仿制药的 IBD 患者有资格参加本研究。再转换患者（再转换队列）与仍在使用生物仿制药的患者（生物仿制药剩余队列）进行匹配。停药的原因分为不良反应（即效果丧失或不良事件）或缓解。使用 Cox 比例风险模型比较意外停药的风险。结果 与生物仿制药其余队列相比，再转换队列中的患者 (n = 44) 更年轻（中位年龄 39.9 岁对比 44.0 岁），女性较多（65.9% 对比 48.9%），且给药间隔更短（中位年龄 48.5 天对比 56.0 天） （n = 127）。因不良反应而停药的比例在再转换组中为 22.7%，在生物仿制药剩余队列中为 13.4%，因缓解而停药的比例分别为 2.3% 和 9.4%。与剩余生物仿制药患者相比，重新转换患者因不良反应而停药的风险增加（调整后 HR 3.7，95% CI：1.0-13.9）。由于客观疾病标志物增加而重新转变的患者比仅因症状而重新转变的患者具有更高的停药率（66.7% vs 23.7%）。结论 重新转变的患者因不良反应而停用英夫利昔单抗的风险增加。再转变似乎与患者和/或疾病有关，而不是与产品有关。临床医生可能会将选择重新转换为其他治疗方案的患者转为其他治疗方案。